Preheat oven to 350 degrees
Line an 8x8" baking pan with parchment on all sides
Add all ingredients except sparkling sugar to the bowl of a food processor
Pulse several times to combine ingredients, then process until the dough comes together into clumps
Squeeze some dough together in your hand to gauge if it is mixed enough
If it holds together well, stop pulsing (alternatively, use a fork to combine sugar, salt, and butter, add vanilla and flour and mix with fork to combine)
Press dough into the pan using your hands, then the bottom of a measuring cup or bench scraper
Sprinkle with sparkling sugar
Pre-slice biscuits prior to baking into your preferred size
Transfer pan to the oven and bake for 35-40 minutes until lightly browned on the edges
Remove from the oven and allow to cool
Reslice bars and enjoy
